The entire disclosure of Japanese Patent Application No. 2008-190200, filed Jul. 23, 2008, is expressly incorporated herein by reference.
1. Technical Field
The present invention relates to a liquid supply device and a liquid ejecting apparatus.
2. Related Art
In the past, there was known an ink jet printer (hereinafter, referred to as “a printer”) as a liquid ejecting apparatus for ejecting a liquid onto a target. The printer performs printing on a print medium as the target by ejecting ink (a liquid) supplied to a printing head (a liquid ejecting unit) through nozzles formed in the printing head. In recent years, as disclosed in JP-A-5-185603, for example, there has been suggested a printer in which a pump driven to pressurize and supply ink to a printing head from an ink cartridge is formed in an ink passage (a liquid supply passage) connecting an ink tank (a liquid supply source) to the printing head.
In the printer disclosed in JP-A-5-185603, a lamination structure formed by laminating an ink passage forming member having a certain shape and a diaphragm forming member having the same outer circumferential shape as that of the ink passage forming member and a flexible property, and an ink passage and a pump chamber are formed inside the lamination structure. That is, the ink passage forming member is provided with a pump chamber forming concave section forming a part of the wall surface of the pump chamber and an ink passage communicating with the pump chamber forming concave section. In addition, an ink introducing port for introducing the ink from the ink cartridge and an ink lead-out port for leading out the ink to the printing head are provided in the pump chamber forming concave section.
The diaphragm forming member is provided with a diaphragm which forms a part of the wall surface on a side of the pump chamber facing the pump chamber forming concave section and is displaceable to increase or decrease the volume of the pump chamber. In addition, the diaphragm forming member is laminated on the ink passage forming member such that the diaphragm faces the pump chamber forming concave section. In this way, in the printer disclosed in JP-A-5-185603, an ink supply device which is compact and simple in an assembly work is realized by forming the ink passage or the pump chamber inside the lamination structure formed by laminating plural constituent members (the ink passage forming member and the diaphragm forming member) having the same outer circumferential shape.
However, in the ink supply device of the printer disclosed in JP-A-5-185603, the pump chamber communicating the ink passage is formed between the facing surfaces of the constituent members which form the lamination structure, by fixing and fastening all of the laminated constituent members by use of fixing members such as bolts in order to simplify the assembly work. Accordingly, due to tolerance caused upon forming the constituent members, a gap may occur in sealing portions of the pump chamber and the like formed between the facing surfaces of the constituent members fixed in the laminated state. Moreover, the ink which has leaked to the outside of the pump chamber from the gap may leak from the ink supply device formed in the lamination structure. When the ink leaks from the ink supply device, a problem occurs in that the inside of the printer is contaminated by the ink.
This problem occurs not only in the above-described ink jet printer, but also in the liquid supply device, which supplies a liquid by use of the pump provided between the facing surfaces of the constituent members fixed in the laminated state so as to form a part of the liquid supply passage, and a liquid ejecting apparatus including the liquid supply device.